الفهرس 
AcknowledgmentOnly 14 pages are availabe for public view
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Abstract
Irrigation canals network in Egypt at all levels suffer from water losses and un-equitable distribution of irrigation water among beneficiaries. So, its modernization became omnipresent to overcome the problem of water shortage at the end of canals. One of the improvement sectors of irrigation canals network is replacing earthen mesqas by raised lined or buried pipes one. In this research, the hydraulic performance of improved irrigation system is explored using actual case study canal, where buried pipes system is applied as improved mesqas system. The actual case study is Al Hadaya canal which is one of the distributary canals that located in Assiut governorate. This canal services 19 mesqas with different lengths according to the area served. The monthly irrigation efficiency after and before the development of mesqa is studied, also the monthly irrigation efficiency for the canal daily operation at periods of irrigation 14, 16 and 18 hours, respectively is studied. The hydraulic performance of mesqas is studied using different scenarios of operation of the mesqa pumping station and served area irrigation. Three scenarios of mesqa valves operation are considered in this study, the first is all the valves are operated at the same time all the week, the second one is every valve operates for one day and the third is every valve operates for two days per week. Also, three scenarios are considered for pump operation 14, 16 and 18 hours per day. Moreover, effect of different scenarios of mesqa operation on sudden transition of flow in pipes due to pump shut-down is studied. EPANET software is used for the hydraulic analysis for two types of mesqas .The first one (mesqa no. (1)) is served by one pump and the second (mesqa no. (9)) is served by two pumps.
Besides, effects of mesqas off-takes on the flow in distributary canal are studied. Irrigation canals are designed such that the flow is constant along the canal, however, the actual flow is spatially varied flow. The variation of water depth in distributary canal for constant and spatially varied flow for the canal operation at periods of irrigation 14, 16 and 18 hours, respectively are studied.
The findings from this study are as follows,
1- operating the pump 14 hours per day fulfill the minimum monthly cost.
Also, operating the outlet valves according to scenario no. (3) i.e. two
day per week gives the least operating cost.
2-The maximum velocity in the pipeline is less than the allowable value
for all operating scenarios.
3- Scenario no. (1) i.e. operating all valves, gives the minimum discharge
for the three pumps operation condition.
4- The smaller head loss is at operation according to scenario no. (2) i.e. for one day per week.
5- Scenario no. (2), i.e. operating one outlet daily gives the minimum
power for all hours of operation.
6- The water depth along the distributary canal for the three scenarios of
mesqa pumps operation, i.e. at 14, 16 and 18 hours respectively
increases by decreasing the hours of pump operation.
7- The constant flow is in the canal results in greater water velocity along
the canal compared with varied flow.
8- The maximum and minimum water velocity along the distributary
canal for the three scenarios of mesqa pumps operation, i.e. at 14, 16
and 18 hours respectively increases by decreasing the hours of pump
operation.